Omni-Justice
by ajjw1121
Summary: What if Ben was sent to the Young Justice Universe shortly before the series started? This story is one possible answer to that question. This story will feature Polyamory. I do not own Young Justice or Ben 10. On Hiatus.
1. Chapter 1

**A/N** : This story will be a retelling of the Young Justice Cartoon Series if Ben Tennyson was sent to that world with no hope of ever returning home. This story starts a month after the end of Ben 10: Ultimate Alien, but Ben will have access to Omniverse Aliens. Zatanna and Rocket are both adults and they will not be part of the Young Justice team. Artemis is a Metahuman and Robin is a magic-user. Thank you very much for reading my story, and **PLEASE LEAVE A REVIEW!**

It had been slightly less than a month since Ben's battle with Diagon, and the world had been at peace ever since. Ben had gotten used to his new Omnitrix which, despite Azmuth's hatred of the feature, still retained the ability to evolve his aliens into their ultimate forms. It now also enhanced all of his physical capabilities and senses while he was in his regular form.

But everything did not remain peaceful, for just as everything seemed to be going great a gigantic ship had appeared in the space near the Earth. Inside were a species called the Contemelia and their device the Anihilaarg, a machine built to destroy and then recreate the universe. After finding out about it the Vreedle Brothers and the Incurseans were on a race to see who could get the Anihilaarg first. Unknown to them there was a third team in the race, led by one Benjamin Kirby Tennyson.

Unfortunately for our heroes the Vreedles got their first, shortly followed by the Incurseans who started a fight with the Vreedles, and during the scuffle the Anihilaarg was accidentally activated. Luckily, before it could finish activating Professor Paradox appeared and froze time.

"Hello Benjamin," Professor Paradox said to the only other person not frozen in time.

"Professor Paradox!" Ben exclaimed, overjoyed at the sight of his long-time allie who had once again saved him. "Thank goodness you're here! What do we do now? How do we stop the Anihilaarg?"

"I'm afraid there is only one way to stop the Anihilaarg, young Benjamin." Professor Paradox said sadly. "It is for you and the Omnitrix to never have existed at all."

"What?!" Ben shouted, sounding shocked and slightly betrayed.

"Yes," Professor Paradox started, "You see the Contemelia only appear in a universe when a being to powerful to be allowed to live has reached their most powerful, and that being young Benjamin, is you. To stop the Contemelia from ever appearing in this universe you and the Omnitrix must never have existed."

"But-But," Ben stammered, "What about all of the good I've done? Stopping Vilgax, the Highbreed, the Incurseans, not to mention Diagon! Without me who would've stopped all of them?"

"Well Benjamin," Paradox began, "Without you and the Omnitrix around Vilgax and the Incurseans would never have taken notice of the Earth, and without Vilgax Diagon would never have been freed in the first place. As for the Highbreed, Gwendolyn and Kevin would have been enough to stop them."

"So, what?" Ben asked him, "Your just going to make me disappear, make it like I never existed in the first place?" Ben said, sounding completely betrayed.

"Of course not!" Paradox said, offended.

"But then-" Ben began, before being interrupted by Paradox.

"Just because you cannot exist here doesn't mean you can't exist in another universe," Paradox started, "A universe in which the Contemelia cannot enter."

"But my friends, my family," Ben said, heartbroken at the implications of never having existed.

"I'm sorry to say they and everyone else in the universe will not remember you," Paradox said, sounding sympathetic, "As I said, it will be as if you never existed."

Ben stood in place for a few moments mourning his life that, in a few moments, would be gone before saying, "Okay, let's do this."

"Of course," Paradox said gently, "But before you go I do have a few gifts for you. The first will be knowledge on the universe you will be entering, and second I will unlock the master control on your new Omnitrix. FInally, I would like you to have this." He says, holding out his hand, and there sitting within his palm is a circular charm with a strange symbol on it.

"The Keystone of Bezel," Ben says in slight awe, taking the charm. "But why give it to me?"

"You will know soon enough," Paradox says with his usual smile before losing it for a more somber look. "Now, are you ready to go?"

Ben takes one last look back at Gwen and Kevin, frozen in time. A single tear falls slowly down his face before he wipes it away, and then he nods as he says, "Yeah, I'm ready to go."

With that Professor Paradox places his hand on Ben's shoulder, and the next thing Ben knows he is standing in the middle of a forest. He feels a slight pain in his head as he suddenly gains all the relevant knowledge needed to survive in this new universe.

"So I guess this is good-bye, huh," Ben says, looking at Professor Paradox.

Professor Paradox gives him a sad nod before saying, "Alas, it looks that way young Benjamin."

"Good-Bye Professor Paradox," Ben bids him farewell sadly.

"Good-Bye young Benjamin," Professor Paradox says before disappearing with a small flash of light.

After a few moments of just standing there, looking at where Professor Paradox had once stood Ben came out of his mood and decided to get walking. Afterall, he had no idea how far away the nearest city was.

He quickly goes over the new knowledge in his head about his new home before saying, "Superheroes, huh? Guess I know what I'm going to be doing with my life."

This is where our story truly begins.

 **~Line Break~**

It had been a little over a month since Ben had come to this new universe and he had yet to find a place to live permanently. He had mostly been staying in hotels, paid for with money he got for his job as a computer technician by using Greymatter to help with the work. He had also made all needed documents to become an actual citizen, including a driver's license, by hacking into the needed websites using Greymatter.

He had finally made enough money to buy his own house, now all he needed was a place to live. Ben had decided to move to place without a huge crime-rate, yet a place that still needed protection. And he found the perfect place in Happy Harbor, Rhode Island.


	2. Chapter 2

**A/N** : I forgot to mention this story will feature some Aliens from the Ben 10 series that Ben had never shown the ability to turn into. Ben is 16, and he has a complete knowledge of every superhero and supervillain that exists in his new universe. Thank you very much for reading my story, and **PLEASE LEAVE A REVIEW!**

Ben had been living in Happy Harbor for about a week when his relatively normal new life was interrupted by a feeling of wrongness in the atmosphere. Even though he himself could not do magic Ben could sense it, and right now he sensed a very large use of magic. Also, from what he could tell, the magic was malevolent in nature.

After pinpointing the magic to Norway, knowing he would be able to sense its location even better once he got closer to it, he transformed into Jetray and flew off at hypersonic speeds.

He finally arrived in Norway, and after finding the precise location of the magical burst he flew their swiftly. When he got there he found it was a clearing in the middle of nowhere, and he experienced a big shock because when he arrived he saw what appeared to be the entire Justice League fighting a single person.

It only took him a moment to overcome his shock once he realized who it was exactly the league was fighting. Wotan, an evil immortal sorcerer that would even give Gwen a run for her money. It was lucky he overcame his shock at that moment as well, for just at the moment Wotan had knocked out the last of the Justice League and was about to complete whatever spell it was he was going to cast.

' _Not on my watch_ ,' Ben thinks to himself as he flies over towards Wotan and quickly shoots him with a Neuroshock blast from his eyes.

"Ah!" Wotan screamed as he was unexpectedly shot in the back. "What?!" He yelled as he turned around to see what looked like a humanoid manta-ray flying right at him.

"Not so fast Wotan!" Ben says as he body-slams into him yet continues flying. Wotan quickly gets back up and shoots a blast of pure magical energy at Ben, which he dodges and continues to fly through the air.

"You can't possibly hope to defeat me," Wotan says as he shoots more magical blasts at Ben, while Ben circles around him at amazing speeds.

"Don't have to," Ben replies as he stops and points behind Wotan. Wotan puts on a confused face and turns around, right into a punch from Superman. With that, Wotan is down for the count.

Superman quickly put a power-dampening collar around his neck before turning to Ben and saying, "Thanks for the help."

"No problem Superman," Ben says before continuing, "I've actually been meaning to meet with you and the rest of the Justice League."

"Oh yeah," Superman says, sounding amused, "And why is that Mr. …"

"I would love to tell you who I am, but I think our first priority should be to make sure your friends are okay, and to take care of Wotan before he wakes up. For now just call me Jetray." Ben says, even as the rest of the Justice League begins to rouse themselves.

"Who's this?" The Flash asks as he zips over to come stand next to Superman. The rest of the League quickly finish waking themselves up and come over to stand near where Superman and the Flash are already standing.

"He says his name is Jetray, and he promised to explain more about himself after we take care of Wotan," Superman explains to the rest of the League. They all nod, though Batman does throw him a suspicious look, before they get ready to go.

Ben promises to stay put until they drop Wotan off with the police. They arrive back at the spot where Ben is waiting after about an hour, and Ben (still in Jetray's form) is still waiting there for them.

"So is your name really Jetray," Green Arrow asks him with a bit of amusement in his voice.

Ben glares at the Green Arrow a little bit before saying, "No, I just said that's what you can call me. My real name is Ben," He says before transforming back into his regular human from & continuing, "Ben Tennyson."

Ben had deliberated for a long time on whether or not he could trust the Justice League with who he was and where he was from, but just last week he had decided he could. After all, with the knowledge Professor Paradox gave him he knew who all of them were, so it was only fair he let them know who he was.

After a few moments the Flash cut the silence by saying, "A kid?! We were saved by a kid?!"

"Hey, this kid just helped take down Wotan." Ben replies, sounding offended and a little annoyed. There were another few moments of silence before it was broken, this time by Martian Manhunter.

"How did you transform into that creature? Jetray, was it?"

"Yeah, well you see it's because of this device," Ben says as he holds up his wrist, the one bearing the Omnitrix. "It's called the Omnitrix and it allows me to transform into any of around 75 different species of aliens, and all of them have different powers and abilities."

"Would you mind showing us a few examples of the Aliens you can turn into?" Batman asks. Ben knows he asks because he has a naturally suspicious nature, and he wants to learn more about him in case he was ever forced to fight him. Ben decided to humor him anyways.

"Sure, no problem," he says before transforming into a humanoid creature made of molten rock and fire. "I call this one Heatblast," He then transforms into another creature, this one appearing like a stereotypical mummy, "This is Snare-Oh," and he then transforms into an alien that looks like a yellow sasquatch, "And this is Shocksquatch." He says before going back to his human form again.

"So, Ben, how come we've never heard of you?" asks Wonder Woman, "People don't gain the necessary skill to take on a villain like Wotan without much field experience. The Justice League closely monitors all heroic activity on Earth and off world, and we've never even heard a whisper about someone with your abilities."

"Well, you see," Ben says as he rubs the back of his head, "That's because I'm not from this universe."


	3. Chapter 3

**A/N** : I made Artemis a Metahuman because I wanted her to have Superpowers, and yes Robin already knows Magic. Ship, the Galvanic Mechamorph, will not be in this story. You're welcome for the (slightly) longer chapter. Thank you very much for reading my story, and **PLEASE LEAVE A REVIEW!**

There was another few moments of silence before it was once again broken, this time by the Flash.

"Another Universe," He says, sounding amused and slightly skeptical. "Really?" The rest of the Justice League weren't taking it much better, with the exception of Superman, Martian Manhunter, Batman, and Wonder Woman.

"And why have you come to our universe?" Batman asks in a dangerous growling voice and with the infamous 'Bat-Glare'. Ben stands there, unintimidated by it, because he has faced things much more scary and dangerous than Batman ever was or ever will be.

"Well, it's a long story," Ben says while rubbing the back of his head, "You see it all begins when the Contemelia, the beings who oversee my universe, appeared. They only appear when a being that is too powerful to live has reached their most powerful, and that being was me. In order to get rid of me they were going to destroy my entire universe, but in order to stop them a friend of mine came up with a compromise. He decided to erase me from existence in my home dimension and send me to another universe to live the rest of my days in, this universe. And that's how I got here."

"Yeah, that's a nice story and all," Green Lantern (John Stewart) says, sounding extremely skeptical, "But what exactly makes a kid like you so powerful?"

"Hey, this kid has saved his home universe more times than he can count," Ben says irritability, talking in the third person. "The only reason I was considered to powerful to live is because I saved my world from the previously most powerful being in my universe. Also, I can prove I was sent here from another universe. That friend that sent me here also gave me all of the knowledge I would need in this world. Including the knowledge of who all of you are."

There was yet another moment of silence before the Flash started laughing, somewhat awkwardly. He then said, "Come on guys, our we really gonna believe this kid. I mean there is absolutely no way he knows who we are."

"Would you like me to prove it?" Ben says smugly.

"Sure, go ahead." The Flash says, equally smug "Everyone else already knows who I am, not like it matters, since there's no possible way you could-".

"Barry Allen," Ben says, cutting off the Flash.

Silence once again, this time awkward and with a slight wave of fear coming from the Justice League.

"Don't worry," Ben says, reassuringly, "I don't plan on revealing any of your identities. I just wanted to prove that I have knowledge I couldn't have unless my story was true. I'll even let Martian Manhunter read my mind to prove that I'm telling the truth."

"J'onn?" Superman asks the Martian. Said Martians eyes glow for a moment and Ben feels a presence within his mind before the Manhunter gasps and his eyes stop glowing.

"The things this child has been through are unspeakable," J'onn says in sadness and slight awe. "He has indeed saved his home dimension numerous times, almost more times than all of us combined have saved the Earth." There were gasps of shock and awe at these statements, as well as pitying stares and some glares of disbelief.

"I'm still having trouble believing that this kid could have saved any world so many times, even if he can turn into some pretty cool looking aliens," the Flash says, still skeptical. "I mean, how long could he have been a hero, a year-maybe two?"

"Actually, I've been a hero for six years now. Ever since I was ten years-old." Ben says, smug at the look of shock on the Flash's face, as well as on the over heroes faces. "Ever since I found the Omnitrix, by accident, during a family camping trip I've been targeted by multiple hostile aliens."

"Not to be rude," Superman cuts in, "But why have you come to contact us?"

"Well, no special reason really," Ben says casually, while grinning, "I just wanted to join the Justice League."

All of the leaguer's look at each other for a moment before Batman speaks up, "We'll think about it, but for now we have some important matters to take care of."

"We'll be in contact with you soon," Superman says, "In the meantime, would you mind telling us where your staying at?"

"Sure," Ben says, "I currently live in Happy Harbor, Rhode Island." He then transforms back into Jetray before saying, "Well, I'd better be off."

"Wait," Batman says, "It would be too confusing to refer to all of your different forms by different names. What should we call you?"

After thinking for a moment Ben then smiles and says, "You can call me Legion."

 **~Line Break~**

The Justice League ended up calling the next day, and they told Ben to meet them at the base of a the mountain outside of Happy Harbor in three days. Ben spends most of the time between those three days working on a secret project in the hidden sub-basement of his new house.

Finally, the day arrived. Ben left very early that day and made it to the base of the mountain in record time, and when he got there a hidden door built into the mountain itself opened up and allowed him entrance.

Once inside he was greeted by Batman, and he was led into a hallway adjoining a large room.

"The league has discussed your unique situation," Batman says, "and has come to the decision that you are to young to join the Justice League." He held up his hand to stop Ben before he could even begin to protest. "Instead, you will be joining a team of other young heroes around the same age as yourself. A covert team that will handle the missions that the Justice League are either too busy or to well known to handle. You will meet your teammates in a few minutes, but for now wait here until your called." Ben nods, and Batman walks away.

From where I'm standing Ben is he can hear Batman talking to what he assumes is the rest of his new team. "This cave was the original secret sanctuary of the Justice League. We're calling it into service again. Since you four are determined to stay together and fight the good fight, you'll do it on League terms."

He pauses before continuing, "Red Tornado has volunteered to live here and be your supervisor, and Black Canary is in charge of training. I will deploy you on missions."

"Real missions?" Ben hears a young male voice ask, carefully.

"Yes," Batman replies, "But covert."

"The League will still handle the obvious stuff," The Flash says, "There's a reason we wear these big targets on our chests."

"But Cadmus proves the villains are getting smarter," Aquaman continues, "We need a team that can operate on the sly."

"The six of you will be that team," Batman finishes.

"Cool," the same young male voice from earlier says, before hesitating and saying, "Wait, six?"

Ben takes that as his cue and begins to walk out before stopping as he hears another set of footsteps walking from the hallway opposite of his.

"This is the Martian Manhunter's niece," Batman says, "Miss Martian."

"Hi," Ben hears a young female voice say nervously.

"I'm liking this gig more and more each minute," A different young male voice says.

"And this," Batman continues, as if he was never interrupted, "Is Ben Tennyson." Ben finally does walk out of his hallway and waves as he finally sees his new teammates. There is a redhead with freckles, an African-American boy with blonde hair and gils, a short brunette with sunglasses on, a tall brunette with a Superman shirt on, and green girl with Auburn hair.

There is a moment of silence before the redhead says, "Uhh, who is this?"

"Like I said," Batman says in his gruff voice, "This is Ben Tennyson. He's a young hero the League met while on a mission a few days ago. After careful deliberation it was concluded that he would be an adequate and trustworthy addition to the team."

"Hi," Ben says, self-assuredly, "You can call me Legion."

"Umm, nice to meet you," the redhead says before introducing himself and the others, "I'm Kid-Flash, that's Aqualad, he's Robin, and this is Superboy." He then turns back to the green girl, Miss Martian, Ben surmises, and says, "But it's okay if you forget their names."

"I'm honored to be included," Miss Martian says, still sounding nervous, and with that Kid-Flash, Robin, Aqualad, and I move closer to Miss Martian. Yet Superboy stays where he's standing.

That is, until Robin turns to him and says, "Hey Superboy, come meet Miss M." And just like that Superboy is walking towards Miss Martian as well, and as he does Miss Martians shirt changes from White to Black.

"I like your shirt," She tells Superboy, who smiles slightly. Robin bumps him with his elbow, and Kid-Flash runs over to his side as Aqualad and Ben look on.

"Today is the day," Aqualad says. Ben nods, thinking that maybe he could get use to this universe.


End file.
